Predictors of unfavourable treatment outcome in patients diagnosed with drug-resistant tuberculosis in the Torres Strait / Papua New Guinea border region

Factors associated with unfavorable treatment outcomes among multidrug-resistant tuberculosis patients, Sierra Leone: a cross-sectional secondary data analysis

BACKGROUND

Globally, multidrug-resistant tuberculosis (MDR-TB) is a major public health problem. The tuberculosis rate in Sierra Leone is 298 per 100,000 people, and Sierra Leone is considered a country with a high burden of tuberculosis. In Sierra Leone, there are few studies on the outcomes of MDR-TB treatment, especially those exacerbated by COVID-19. We identified factors associated with unfavorable treatment outcomes among people with MDR-TB in Sierra Leone.

METHODS

We conducted a cross-sectional study to analyze hospital-based MDR-TB data from 2017 to 2021. Demographic, clinical, and treatment outcome data were extracted from the main MDR-TB referral hospital database. We defined unfavorable outcomes as patients who died, were lost to follow-up, or defaulted. We calculated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to identify predictors of the outcomes of MDR-TB treatment.

RESULTS

Between 2017 and 2021, 628 people with MDR-TB were reported at Lakka Hospital; 441 (71%) were male, with a median age of 25 years (interquartile ranges: 17-34). Clinically, 21% of the 628 MDR-TB patients were HIV positive, and 413 were underweight (66%). 70% (440) of MDR-TB patients received tuberculosis treatment. The majority of patients, 457 (73%), were treated with a short treatment regimen, and 126 (20%) experienced unfavorable outcomes. Age 45 years or younger (aOR = 5.08; CI:1.87-13.82), 21-45 years (aOR = 2.22; CI:140-3.54), tuberculosis retreatment (aOR = 3.23; CI:1.82-5.73), age group, HIV status (aOR = 2.16; CI:1.33-3.53), and malnourishment status (aOR = 1.79; CI:1.12-2.86) were significantly associated with unfavorable treatment outcomes for DR-TB patients.

CONCLUSION

This analysis revealed a high proportion of unfavorable treatment outcomes among MDR-TB patients in Sierra Leone. Malnourishment, TB retreatment, HIV coinfection, and age 45 years or younger were associated with unfavorable outcomes of MDR-TB treatment. Increasing patients' awareness, mainly among young people, heightens treatment adherence and HIV monitoring by measuring the amount of HIV in patient blood, which can reduce adverse treatment outcomes in Sierra Leone and other sub-Saharan African countries.

Predictors of unfavourable treatment outcome in patients diagnosed with drug-resistant tuberculosis in the Torres Strait / Papua New Guinea border region

Drug-resistant tuberculosis (DR-TB) is an ongoing challenge in the Torres Strait Islands (TSI) / Papua New Guinea (PNG) border region. Treatment success rates have historically been poor for patients diagnosed with DR-TB, leading to increased transmission. This study aimed to identify variables associated with unfavourable outcome in patients diagnosed with DR-TB to inform programmatic improvements. A retrospective study of all DR-TB cases who presented to Australian health facilities in the Torres Strait between 1 March 2000 and 31 March 2020 was performed. This time period covers four distinct TB programmatic approaches which reflect Australian and Queensland Government decisions on TB management in this remote region. Univariate and multivariate predictors of unfavourable outcome were analysed. Unfavourable outcome was defined as lost to follow up, treatment failure and death. Successful outcome was defined as cure and treatment completion. In total, 133 patients with resistance to at least one TB drug were identified. The vast majority (123/133; 92%) of DR-TB patients had pulmonary involvement; and of these, 41% (50/123) had both pulmonary and extrapulmonary TB. Unfavourable outcomes were observed in 29% (39/133) of patients. Patients living with human immunodeficiency virus, renal disease or diabetes (4/133; 4/133; 3/133) had an increased frequency of unfavourable outcome (p <0.05), but the numbers were small. Among all 133 DR-TB patients, 41% had a low lymphocyte count, which was significantly associated with unfavourable outcome (p <0.05). We noted a 50% increase in successful outcomes achieved in the 2016-2020 programmatic period, compared to earlier periods (OR 5.3, 95% Confidence Interval [1.3, 20.4]). Being a close contact of a known TB case was associated with improved outcome. While DR-TB treatment outcomes have improved over time, enhanced surveillance for DR-TB, better cross border collaboration and consistent diagnosis and management of comorbidities and other risk factors should further improve patient care and outcomes.